Applicant's prior U.S. Pat. No. 7,568,438, the entirety of which is incorporated herein by reference, discloses a disc furrow opener in which a scraper is carried alongside the disc to clear soil buildup therefrom, while also forming a shelf in the side of the disc-cut furrow to enable separate placement of seed and fertilizer at the shelf and the furrow bottom. A leading front edge of the scraper resides in contact or close proximity to the disc to perform the scraping action, and the scraper angles obliquely outward from this edge to form a space between the disc and the scraper into which seed and fertilizer are safely delivered to the shelved furrow behind the cover of the scraper. Select embodiments includes a carbide wing projecting laterally from the scraper at the outer side thereof opposite the disc in order to widen the shelf area cut into the side of the primary furrow.
U.S. Pat. No. 7,540,246, the entirety of which is incorporated herein by reference, also teaches a disc furrow opener with a winged scraper, but the wing is formed integrally with the scraper and cuts into the wall of the disc's primary furrow, rather than into a scraper-formed shelf area.
In use of Applicant's prior design, it has been found that straw may become wrapped up between the scraper and the disc at the front portion of the scraper that angles obliquely outward from the disc in trailing relation to the leading scraper edge. Also, side load forces exerted on the scraper toward the disc during use are concentrated on the leading edge's small contact area with the disc, which may therefore wear at a notable rate. Additionally, seeds inadvertently bouncing forward when dropped into the furrow can become trapped in the tapered space between the disc and angled front portion of the scraper, or escape through any small space that may be open between the leading scraper edge and the disc.
In the case of a wing used to widen a scraper-formed shelf or open a slot in the primary furrow of the disc, use of carbide to form the entirety of the wing increases the cost of the winged scraper versus selective use of carbide at only the most wear-prone leading and outer edge of the wing.
Accordingly, there remains room for improvement of scraper-equipped disc openers. Applicant discloses herein unique opener designs and methods that may be useful to solve or mitigate the foregoing shortcomings of the prior art.